## Organizing Data with a Matrix

In the first video, we are going to organize data with a matrix.

Let’s first define matrix:

**Matrix:** A rectangular array of data such as numbers and symbols.

**For example:**

Let’s call the matrix *A*. Therefore:

A_{1},_{1} = 85 and

A_{3},_{2} = 86

## Adding and Subtracting Matrices

In the second video, we are going to add and subtract data with a matrix.

To do so, we can simply either add or subtract the values in the corresponding locations in the given matrices. Note that only matrices of the same size can be added or subtracted.

**For example:**

And here is another one

## Multiplying a Matrix by a Scalar Number

In the third video, we are going to multiply matrix by a scalar.

We can simply multiply the scalar number by each value inside the matrix.

**For example:**

## Multiplying a Matrix by a Matrix

In the fourth video, we are going to multiply matrix with a matrix.

If the matrices have different sizes, multiply the corresponding numbers but of different orientations.

**For example:**

Since the first matrix is *2×3* and the second matrix is *3×2*, your answer is a 2×2 matrix. To get the value of , multiply each number of the** first row** in the **first matrix** by the corresponding number in the** first column** of the **second matrix**, and add the products (Ex:2×5+6×4+1×6). To get the value of , multiply each number of the **first row** in the **first matrix** by the corresponding number in the **second column** of the **second matrix**, and add the products. To get the value of , multiply each number of the **secobd row** in the **first matrix** by the corresponding number in the** first column** of the **second matrix**, and add the products. To get the value of , multiply each number of the **second row** in the **first matrix** by the corresponding number in the **second column** of the **second matrix**, and add the products.

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